The purpose of the pressure balancing passages is to soften the shock effect of the pressure changes in the cylinder chambers arising in the transition region between the low pressure (LP) region and the high pressure (HP) region. This purpose is served by the pressure balancing passages through which a relatively gentle adaptation of the pressures in the cylinder chambers to one another occurs before the cylinder opening of the respective cylinder chamber lies in the cross-sectional region of the HP passage. By reducing the abrupt effect of the pressure changes in the cylinder chambers the running noise of the axial piston machine due to the abrupt effect can be reduced.
With the known pressure balancing passages the running noise of the axial piston machines can indeed be reduced, but the pressure balancing passages lead to damage to the axial piston machine by wear, namely to erosion of the walls against which the jets of fluid emerging from the pressure balancing passages strike, namely in particular:
jet erosion of the control passage walls in the cylinder, and PA1 cavitation erosion of the control surface and of the bearing surface of the control plate.
Damage of this kind occurs in both pump and motor operation of the axial piston machine.